1. The Field of the Invention
The present invention is directed generally to architectural building blocks for constructing cylinders and arches. More specifically, the present invention is directed to masonry architectural building blocks for constructing cylinders and arches.
2. Background Art
In fabricating structures composed of curvilinear parts, typically forms are required for concrete pouring as conventional blocks are often unsuitable for constructing such parts as conventional masonry blocks are unsuitable due to their shapes and sizes. On-site constructions of structures using forms often involve significant custom architectural and engineering preparation work, which not only increases the construction cost but also the lead time in completing the construction projects. Even if conventional masonry blocks are used to construct curvilinear parts, sufficient skills are required to custom shape some masonry blocks so that they can fit in with other unmodified blocks to approximate the structural shape to be constructed. Conventional blocks used for curvilinear parts include rectangular and triangular blocks, etc. In many occasions, sufficient skills may also be required to adjust the amount of mortar used between blocks such that curvilinear parts can be constructed. When built without forms or other supporting structures, the use of conventional blocks does not yield uniform, accurate and repeatable arch structures. It may even be impossible to construct a curvilinear structure using conventional blocks if mortar had not been used.
U.S. Pat. No. 2,392,551 to Roe (hereinafter Roe) discloses a wall structure having a series of superposed courses of building blocks, matching keyways in certain adjacent blocks in a course and keys in the keyways locking the adjacent blocks together. Each of the keys extends from one course into and fits snugly within an opening in a block of an adjacent course, thereby locking adjacent courses together against horizontal shifting, and tongue and groove connections inclined to the longitudinal axes of the keys and interlocking blocks of adjacent courses whereby the first named keys and the tongue and groove connections lock the courses against vertical as well as horizontal shifting, the tongues of the tongue and groove connections being each integral with a block. Although a means for interlocking adjacently disposed blocks is provided, Roe fails to disclose building blocks useful for building arches when used in conjunction with only two rebars.
U.S. Pat. Pub. No. 2013/0205705 of Bilka (hereinafter Bilka) discloses a masonry article having one or more sidewalls, top and bottom, and first and second ends configured with a horizontal and vertical locking mechanism, wherein top and bottom includes first axis locking mechanism, wherein the top surface is formed with at least one stepped section having a base that begins with a level footing and the bottom opposite surface formed with at least one other stepped section having a base that begins with a level footing to releasably receive one of the top, and wherein first and second ends include contoured receptacles to releasably receive a matching configured link block having opposite male contour surface to form second axis locking mechanism. Similar to Roe, Bilka fails to disclose building blocks useful for building arches when used in conjunction with only two rebars. Instead, Bilka discloses blocks useful for building cylindrical structures although such structures of Bilka do not contain corrugations and/or ribs that are capable of further resisting against external loading, impacts, high winds, seismic forces, etc.
Thus, there is a need for blocks useful for constructing arches and cylinders that are capable of resisting environmental forces and ones which can be built without using pre-fabricated or in-situ built forms and temporary support structures or scaffolding systems.